Administration Guide › Setting Up Reservation Manager › Chargeback › Modify the Physical System Allocation Policy › How the Low Cost Algorithm Works

How the Low Cost Algorithm Works

The weighted algorithm is used with a preferred pool policy. The administrator defines the order of resource pools to search for resources that match a user request. If systems are available in the primary pool, the weighted algorithm is applied to determine which system is the best match. Secondary resource pools are only searched if a match cannot be found in the primary pool, even if the secondary pools have a closer matching system based on the weighting algorithm.

A weighted algorithm selects the physical system that most closely matches the user requirements. This algorithm weights the following system properties by default:

• Number of CPUs—weights each CPU at 500
• Available memory—weights each available gigabyte of memory at 50
• Hard disk space—weights each gigabyte of hard disk space at 2

Therefore, one CPU costs approximately the same as 10 GB of RAM and 250 GB of hard disk space using the default policy.